CN111750483A

CN111750483A - Air conditioning system pressure protection control method and air conditioner

Info

Publication number: CN111750483A
Application number: CN202010443870.1A
Authority: CN
Inventors: 郭玮; 韩雷; 刘仁东
Original assignee: Aux Air Conditioning Co Ltd; Ningbo Aux Electric Co Ltd
Current assignee: Aux Air Conditioning Co Ltd; Ningbo Aux Electric Co Ltd
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2020-10-09

Abstract

The invention provides a pressure protection control method of an air conditioning system and an air conditioner, wherein the air conditioning system comprises a refrigerant circulating flow channel which connects a compressor, an evaporator and a condenser together in series, a first throttling component is arranged on the refrigerant circulating flow channel, the air conditioning system also comprises a bypass branch, the bypass branch is connected with the evaporator and the condenser in parallel, a second throttling component is arranged on the bypass branch, and the control method comprises the following steps: judging and controlling to enter a pressure protection program according to the pressure of the exhaust pipe of the compressor; and adjusting the load of the air conditioning system and/or adjusting the compression ratio of the air conditioning system through the bypass branch to adjust the pressure of the air conditioning system. The invention reflects the real-time pressure of the air-conditioning system by detecting the pressure of the exhaust pipe of the compressor, is more real and reliable, effectively avoids the error and lag of the detection of the pressure value of the air-conditioning system, mixes the refrigerant throttled twice and the refrigerant returning from the evaporation side by arranging the bypass branch, reduces the compression ratio of the air-conditioning system, and accurately and timely controls the pressure value of the system within a reasonable range.

Description

Air conditioning system pressure protection control method and air conditioner

Technical Field

The invention relates to the technical field of air conditioners, in particular to a pressure protection control method of an air conditioner system and an air conditioner.

Background

Currently, with the continuous improvement of living standard of people, air conditioners are very popular and common, wherein a compressor is arranged in an outdoor unit as a core component of the air conditioner, the outdoor environment is severe, and especially in high-temperature weather in summer and cold seasons in winter, the outdoor unit often generates high-pressure or low-pressure faults to cause system pressure abnormality. Therefore, in order to ensure the safe and reliable operation of the compressor, reduce and avoid after-sale complaints of air conditioner users, and ensure the life and property safety of the users, various protective measures are generally set for the compressor.

For the control of the pressure of an air conditioning system, the control is basically carried out through the temperature of an inner coil and an outer coil when the air conditioning system operates at present, for example, the patent named as an air conditioning pressure protection system, an air conditioning refrigeration pressure protection method and an air conditioning heating pressure protection method in the prior art discloses a method for simulating the system pressure through the temperature of the inner coil and the outer coil obtained by a temperature sensor, and the system pressure is adjusted by reducing the frequency of a compressor and increasing the opening degree of an electronic expansion valve, so that the system pressure is in a normal range in the air conditioning refrigeration and heating processes, and high-pressure/low-pressure faults are avoided.

However, the above control method for simulating the system pressure by the inner and outer coil pipe temperature has the following disadvantages: firstly, the collected data of the temperatures of the inner and outer coil pipes cannot reflect the pressure value of the air conditioning system most truly; secondly, the rationality and the difference of the positions of the inner coil and the outer coil increase the fluctuation and the difference of pressure value detection data of the air-conditioning system; third, the collection of the inner and outer coil temperature data results in hysteresis in the pressure control action of the air conditioning system. Therefore, how to provide a method capable of truly and accurately reflecting the pressure of the air conditioning system and ensuring the safe and reliable operation of the compressor is a problem to be solved urgently at present.

Disclosure of Invention

In view of this, the present invention provides an air conditioning system pressure protection control method and an air conditioner, so as to solve the problem that a compressor is prone to malfunction due to the fact that the pressure of the air conditioning system cannot be truly and accurately reflected in the prior art.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a pressure protection control method of an air conditioning system comprises a refrigerant circulating flow channel and a bypass branch, wherein the refrigerant circulating flow channel is formed by connecting a compressor, an evaporator and a condenser in series, a first throttling assembly is arranged on the refrigerant circulating flow channel, the bypass branch is connected with the evaporator and the condenser in parallel, a second throttling assembly is arranged on the bypass branch, and the control method comprises the following steps:

judging and controlling to enter a pressure protection program according to the pressure of the exhaust pipe of the compressor;

and adjusting the load of the air conditioning system and/or adjusting the compression ratio of the air conditioning system through the bypass branch to adjust the pressure of the air conditioning system. The real-time pressure of the air conditioning system is reflected by the pressure of the exhaust pipe of the compressor, so that the method is more real and reliable compared with the prior art, the error and the lag of the detection of the pressure value of the air conditioning system are effectively avoided, and the pressure value of the system is accurately and timely controlled within a reasonable range by the controller of the air conditioning system; through setting up the bypass branch road for can adjust air conditioning system's pressure through adjusting air conditioning system's compression ratio, mix the low temperature refrigerant after twice the throttle with the refrigerant that returns from the evaporimeter side, reduce air conditioning system's compression ratio, prevent that air conditioning system compressor is overheated and compress and press the ratio too high, effectively avoid causing the air conditioner of a period to shut down unusually because of pressure protection, improve user's use reliability and promote user's experience degree.

Further, when the pressure Ph of the compressor exhaust pipe meets a first preset condition, a pressure protection program is controlled to be executed to adjust the pressure of the air conditioning system, and the bypass branch is closed when the pressure of the air conditioning system is adjusted until the pressure of the compressor exhaust pipe meets a second preset condition.

Further, the method for adjusting the pressure of the air conditioning system comprises the following steps:

reducing the air inlet amount of the evaporator side and/or reducing the compression ratio of an air conditioning system;

the air inlet amount of the condenser side is increased and/or the compression ratio of an air conditioning system is reduced;

reducing the running frequency of the compressor and/or reducing the compression ratio of the air conditioning system;

at least one of the above three ways. The pressure of the air conditioning system is adjusted by adjusting the load of the air conditioning system and reducing the compression ratio of the air conditioning system, so that the air conditioning system is more real and reliable, the compressor is effectively prevented from breaking down, the pressure of the air conditioning system is adjusted by preferentially considering the mode of adjusting the load of the air conditioner, and the normal heat exchange of the air conditioning system is ensured.

Further, the process of reducing the air inlet amount on the evaporator side and/or reducing the compression ratio of the air conditioning system comprises the following steps:

when the fan on the corresponding side of the evaporator is in a non-lowest windshield, reducing the air inlet volume of the fan on the evaporation side, and keeping the compressor in normal power-on operation; when the fan on the corresponding side of the evaporator is the lowest windshield and the pressure Ph of the compressor exhaust pipe meets a first preset condition, the compression ratio of the air conditioning system is reduced by opening the bypass branch. When the air inlet volume of the fan at the evaporator side is reduced and the pressure Ph of the exhaust pipe of the compressor does not meet the first preset condition, the reduction of the air inlet volume at the evaporator side causes the load reduction of the air conditioner, so that the pressure of the air conditioning system is reduced. When the pressure Ph of the exhaust pipe of the compressor still meets a first preset condition after the air inlet volume of the fan at the evaporator side is reduced, the air inlet volume at the evaporator side is reduced to be insufficient to sufficiently reduce the pressure of the air conditioning system, and the compression ratio of the air conditioning system needs to be reduced or the air inlet volume of the fan at the evaporator side needs to be further reduced; when the fan on the corresponding side of the evaporator is the lowest windshield and the pressure Ph of the compressor exhaust pipe meets a first preset condition, the pressure of the air-conditioning system is higher when the fan on the evaporator side runs with the current lowest windshield, the normal and stable running of the air-conditioning system is influenced, the compressor is prone to failure, and the bypass branch needs to be opened to reduce the pressure of the air-conditioning system by reducing the compression ratio of the air-conditioning system.

Further, after the third duration delta T3 of the air blower windshield on the evaporator side is reduced, the pressure Ph of the exhaust pipe of the compressor is continuously detected, when the pressure Ph of the exhaust pipe of the compressor does not meet a first preset condition, the air blower on the evaporator side keeps running of the windshield, and when the pressure Ph of the exhaust pipe of the compressor is continuously detected to meet a second preset condition, the bypass branch is kept in a closed state. When the compressor exhaust pipe pressure Ph does not meet the first preset condition, the load of the air conditioner is reduced due to the fact that the air inlet amount on the evaporator side is reduced, and therefore the pressure of the air conditioning system is reduced. When the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, the air inlet quantity on the evaporator side is reduced to be insufficient for sufficiently reducing the pressure of the air conditioning system, and the compression ratio of the air conditioning system needs to be reduced or the air inlet quantity of a fan on the evaporator side needs to be further reduced.

Further, after the bypass branch is opened and the air conditioning system operates for a third time period delta T3, when the pressure Ph of the compressor exhaust pipe meets a first preset condition, the alarm device of the air conditioning system gives a high-pressure protection operation early warning, and when the pressure Ph of the compressor exhaust pipe does not meet the first preset condition and the pressure Ph of the compressor exhaust pipe meets a second preset condition, the bypass branch is closed. When the bypass branch is opened, after the air conditioning system operates in the current state for a third time period delta T3, and when the pressure Ph of the exhaust pipe of the compressor still meets a first preset condition, the pressure of the air conditioning system cannot be fully reduced by reducing the air intake at the condenser side and reducing the compression ratio of the air conditioner, an alarm prompt needs to be given, and the air conditioning system is manually maintained; when the bypass branch is opened, after the air-conditioning system operates in the current state for a third time period delta T3, when the pressure Ph of the compressor exhaust pipe does not meet a first preset condition, the pressure of the air-conditioning system can be reduced by opening the bypass branch and reducing the pressure-regulating compression ratio, whether the pressure Ph of the compressor exhaust pipe is reduced to a range which ensures normal and stable operation of the air-conditioning system needs to be detected, and when the pressure Ph of the compressor exhaust pipe meets a second preset condition, the pressure of the air-conditioning system is reduced to the range which ensures normal and stable operation, and the bypass branch needs to be closed.

Further, the process of increasing the air intake of the condenser side and/or reducing the compression ratio of the air conditioning system comprises:

when the fan at the condenser side is in a non-highest windshield, the air inlet volume of the fan at the condenser side is increased, and the compressor keeps normal power-on operation; when the fan on the condenser side is the highest windshield and the pressure Ph of the compressor exhaust pipe meets a first preset condition, the compression ratio of the air conditioning system is reduced by opening the bypass branch. After the air inlet volume of the fan at the condenser side is increased and the pressure Ph of the exhaust pipe of the compressor does not meet a first preset condition, the fact that the air inlet volume of the fan at the condenser side is increased causes load reduction of an air conditioner is explained, and therefore the pressure of an air conditioning system is reduced; when the pressure Ph of the exhaust pipe of the compressor still meets the first preset condition after the air inlet amount of the fan at the condenser side is increased, the situation that the pressure of the air conditioning system is not sufficiently reduced by increasing the fan at the condenser side is shown, and the compression ratio of the air conditioning system needs to be reduced or the air inlet amount of the fan at the condenser side needs to be further increased.

Further, after the third duration delta T3 of the damper of the fan on the condenser side is increased, the pressure Ph of the exhaust pipe of the compressor is continuously detected, when the pressure Ph of the exhaust pipe of the compressor does not meet a first preset condition, the fan on the condenser side keeps the damper running, and when the pressure Ph of the exhaust pipe of the compressor is continuously detected to meet a second preset condition, the bypass branch is kept in a closed state. When the pressure Ph of the exhaust pipe of the compressor does not meet the first preset condition, the load of the air conditioner is reduced due to the fact that the air inlet volume of a fan on the condenser side is increased, and therefore the pressure of an air conditioning system is reduced; when the pressure Ph of the exhaust pipe of the compressor still meets a first preset condition, the pressure of the air conditioning system is not sufficiently reduced by increasing the fan at the condenser side, and the compression ratio of the air conditioning system needs to be reduced or the air intake of the fan at the condenser side needs to be further increased; when the compressor exhaust pipe pressure Ph is detected to meet the second preset condition, the air conditioning system pressure can be reduced to be within a normal range by increasing the air inlet quantity on the condenser side.

Further, after the bypass branch is opened and the air conditioning system operates for a third time period delta T3, when the pressure Ph of the compressor exhaust pipe meets a first preset condition, the alarm device of the air conditioning system gives a high-pressure protection operation early warning, and when the pressure Ph of the compressor exhaust pipe does not meet the first preset condition and the pressure Ph of the compressor exhaust pipe meets a second preset condition, the bypass branch is closed. When the bypass branch is opened, after the air conditioning system operates in the current state for a third time period delta T3, when the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, it is shown that the pressure of the air conditioning system cannot be fully reduced by increasing the air inlet amount at the condenser side and reducing the compression ratio of the air conditioner, an alarm prompt needs to be made, and the air conditioning system is manually maintained; when the bypass branch is opened, after the air conditioning system operates in the current state for a third time period delta T3, when the pressure Ph of the compressor exhaust pipe does not meet a first preset condition, it is indicated that the pressure of the air conditioning system can be reduced by reducing the compression ratio of the air conditioner, and whether the pressure Ph of the compressor exhaust pipe is reduced to a range for ensuring normal and stable operation of the air conditioning system needs to be detected.

Further, the process of reducing the operating frequency of the compressor and/or reducing the compression ratio of the air conditioning system comprises:

when the frequency of the compressor is not the lowest frequency, the operation frequency of the compressor is reduced, and when the operation frequency of the compressor is the lowest frequency and the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, the compression ratio of the air-conditioning system is reduced by opening the bypass branch. When the compressor exhaust pipe pressure Ph does not meet the first preset condition after the operation frequency of the compressor is reduced, the reduction of the operation frequency of the compressor causes the load reduction of the air conditioner, and therefore the pressure of the air conditioning system is reduced. When the compressor exhaust pipe pressure Ph still meets the first preset condition after the compressor operation frequency is reduced, the reduction of the compressor operation frequency is not enough to sufficiently reduce the pressure of the air conditioning system, and the compression ratio of the air conditioning system needs to be reduced or the compressor operation frequency needs to be further reduced. When the compressor of the air-conditioning system runs at the lowest frequency and the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, the pressure of the air-conditioning system is higher when the compressor runs at the current lowest frequency, the normal and stable running of the air-conditioning system is influenced, the fault of the compressor is easy to occur, and the bypass branch is required to be opened to reduce the pressure of the air-conditioning system by reducing the compression ratio of the air-conditioning system.

Further, after the third time duration delta T3 of the compressor operation frequency is reduced, the compressor exhaust pipe pressure Ph is continuously detected, when the compressor exhaust pipe pressure Ph does not meet a first preset condition, the compressor keeps operating at the current frequency, and when the compressor exhaust pipe pressure Ph is detected to meet a second preset condition, the bypass branch is kept in a closed state. When the compressor discharge pipe pressure Ph does not satisfy the first preset condition, it is illustrated that the air conditioner load is reduced due to the reduction of the compressor operation frequency, thereby reducing the air conditioning system pressure. When the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, the operation frequency of the compressor is not reduced enough to sufficiently reduce the pressure of the air conditioning system, and the compression ratio of the air conditioning system needs to be reduced or the operation frequency of the compressor needs to be further reduced.

Further, after the bypass branch is opened and the air conditioning system operates for a third time period delta T3, when the pressure Ph of the compressor exhaust pipe meets a first preset condition, the alarm device of the air conditioning system gives a high-pressure protection operation early warning, and when the pressure Ph of the compressor exhaust pipe does not meet the first preset condition and the pressure Ph of the compressor exhaust pipe meets a second preset condition, the bypass branch is closed. When the bypass branch is opened, after the air conditioning system operates in the current state for a third time period delta T3, and when the pressure Ph of the exhaust pipe of the compressor still meets a first preset condition, the pressure of the air conditioning system cannot be sufficiently reduced by reducing the operating frequency of the compressor and the compression ratio of the air conditioner, an alarm prompt needs to be given, and the air conditioning system is manually maintained; when the bypass branch is opened, after the air-conditioning system operates in the current state for a third time period delta T3, when the pressure Ph of the compressor exhaust pipe does not meet a first preset condition, the pressure of the air-conditioning system can be reduced by reducing the pressure-regulating compression ratio, whether the pressure Ph of the compressor exhaust pipe is reduced to a range which ensures normal and stable operation of the air-conditioning system needs to be detected, at the moment, the pressure Ph of the compressor exhaust pipe meets a second preset condition, the pressure of the air-conditioning system is reduced to the range which ensures normal and stable operation, and the bypass branch needs to be closed.

Further, the first preset condition is as follows: and the pressure Ph of the exhaust pipe of the compressor is greater than or equal to a first set value P1 in any continuous second time period delta T2, the second time period delta T2 is set according to the property of the compressor, and the first set value P1 is a high-pressure critical value influencing the stable operation of the air conditioning system.

Further, the second preset condition is as follows: the compressor discharge pipe pressure Ph is less than a first set point P1 for a third duration Δ T3, where the first set point P1 is a pressure threshold that affects stable operation of the air conditioning system.

Compared with the prior art, the air conditioning system pressure protection control method has the following advantages:

the real-time pressure of the air conditioning system is reflected by the pressure of the exhaust pipe of the compressor, so that the method is more real and reliable compared with the prior art, the error and the lag of the detection of the pressure value of the air conditioning system are effectively avoided, and the pressure value of the system is accurately and timely controlled within a reasonable range by the controller of the air conditioning system; through setting up the bypass branch road, make can be through the pressure of adjusting air conditioning system's compression ratio regulation air conditioning system, mix the low temperature refrigerant after twice throttle with the refrigerant that returns from the evaporation side, reduce the compression ratio of air conditioner system, prevent that the air conditioning system compressor is overheated and the pressure ratio is too high, effectively avoid causing the air conditioner of a period to shut down unusually because of high-pressure protection, safety and reliability with guaranteeing the air conditioner, the life of extension air conditioner, promote user's use travelling comfort

The present invention also provides an air conditioner, including a computer readable storage medium storing a computer program and a processor, where the computer program is read and executed by the processor to implement the air conditioning system pressure protection control method, and the air conditioner further includes: the detection unit is used for detecting the exhaust pressure of the compressor and acquiring the running time of the air conditioning system;

a judging unit for judging the size of the compressor relative to a first set value;

and the control unit is used for controlling the air conditioner to adjust the rotating speed of the indoor fan or the outdoor fan and the running frequency of the compressor according to the judgment results of the detection unit and the judgment unit.

Compared with the prior art, the air conditioner and the pressure protection control method of the air conditioning system have the same advantages, and are not repeated herein.

Drawings

FIG. 1 is a schematic structural diagram of an air conditioning system according to an embodiment of the present invention during cooling;

fig. 2 is a schematic structural diagram of an air conditioning system according to an embodiment of the present invention during heating;

fig. 3 is a schematic view illustrating a flow direction of a refrigerant during refrigeration of the air conditioning system according to the embodiment of the present invention;

fig. 4 is a schematic view illustrating a flow direction of a refrigerant when the air conditioning system heats according to the embodiment of the present invention;

fig. 5 is a schematic flow chart of a pressure protection control method of an air conditioning system according to an embodiment of the present invention;

FIG. 6 is a flow chart of a pressure protection control method for reducing the intake air quantity at the evaporator side and/or reducing the compression ratio of the air conditioning system according to the embodiment of the invention;

FIG. 7 is a schematic flow chart of a pressure protection control method for increasing the air intake rate on the condenser side and/or reducing the compression ratio of the air conditioning system according to an embodiment of the present invention;

fig. 8 is a flow chart illustrating a pressure protection control method for reducing the operation frequency of the compressor and/or reducing the compression ratio of the air conditioning system according to an embodiment of the present invention.

Description of reference numerals:

1-compressor, 2-air outlet pipe, 3-four-way valve, 4-outdoor heat exchanger, 5-filter, 6-first throttling component, 7-indoor heat exchanger, 8-solenoid valve, 9-second throttling component, 10-gas-liquid separator, 11-air return pipe, 12-bypass branch, 21-sensor, 41-first fan, 71-second fan

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

The invention provides a pressure protection control method of an air conditioning system, as shown in figures 1-5, the air conditioning system comprises a refrigerant circulating flow channel which connects a compressor, an evaporator and a condenser together in series, a first throttling component is arranged on the refrigerant circulating flow channel, meanwhile, a bypass branch is also arranged on the refrigerant circulating flow channel, the bypass branch is connected with the evaporator and the condenser in parallel, and a second throttling component is arranged on the bypass branch.

The pressure protection control method of the air conditioning system comprises the following steps:

step S1, receiving an operation instruction and operating in a set mode;

after the air conditioning system is started, an operation instruction input by a user is received, the compressor is electrified to operate, meanwhile, the evaporator and the condenser operate according to a set windshield, and the compressor operates according to a set frequency. Specifically, when the air conditioner receives a refrigeration mode operation instruction, the indoor heat exchanger serves as an evaporator, and the outdoor heat exchanger serves as a condenser; when the air conditioner receives the heating mode operation instruction, the outdoor heat exchanger is used as an evaporator, and the indoor heat exchanger is used as a condenser.

Step S2, judging and controlling to enter a pressure protection program according to the pressure Ph of the compressor exhaust pipe;

the method comprises the steps that the compressor exhaust pipe pressure Ph starts to be obtained after the compressor operates for the first time period delta T1, the detected compressor exhaust pipe pressure Ph can truly and accurately reflect the pressure value of the air conditioning system, and the detected data are prevented from being inaccurate. The first time period Δ T1 is a time interval from the compressor being powered on to the stable operation, and specifically, the first time period Δ T1 is set according to the performance of the compressor, and may be set to 0.5-1.5 min, for example, and preferably, the first time period Δ T1 is 1 min.

When the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, the condition that the pressure of the air conditioning system is too high is indicated, the pressure of the air conditioning system needs to be reduced, namely, a pressure protection program is controlled to be executed, and the high-pressure fault of the compressor is prevented. When the pressure Ph of the exhaust pipe of the compressor does not meet the first preset condition, the pressure of the air conditioning system is in a normal range, the air conditioner can stably and normally operate, and the air conditioner continues to operate in the current set mode.

Specifically, the first preset condition is as follows: the compressor discharge pipe pressure Ph is greater than or equal to the first setpoint P1 for any consecutive second duration Δ T2. The second time length delta T2 is set according to the property of the compressor, the first set value P1 is a high-pressure critical value influencing the stable operation of the air conditioning system, the first set values P1 corresponding to different types of refrigerants are different, for example, R32 refrigerant is taken as an example, the P1 value is set to be 4-4.5 MPa; the second time period delta T2 is 1-10 s, and preferably, the second time period delta T2 is 5 s.

And step S3, adjusting the load of the air conditioning system and/or adjusting the compression ratio of the air conditioning system through the bypass branch to adjust the pressure of the air conditioning system.

Adjusting the air conditioning system load comprises: the evaporator heat exchange amount and/or the condenser heat exchange amount and/or the compressor operation frequency are/is changed.

The method for reducing the compression ratio of the air conditioning system comprises the following steps: and opening the bypass branch, throttling part of the low-temperature refrigerant throttled by the first throttling assembly to be throttled again by the second throttling assembly on the bypass branch, mixing the refrigerant throttled twice with the refrigerant returning from the evaporator side, and reducing the compression ratio of the air-conditioning system to reduce the pressure of the air-conditioning system.

When the step S2 judges that the air conditioning system pressure is too high, the air conditioning system pressure is reduced by changing the evaporator heat exchange amount and/or the condenser heat exchange amount and/or the compressor operation frequency to reduce the air conditioning system load; or when the step S2 judges that the pressure of the air conditioning system is too high, reducing the pressure of the air conditioning system in a mode of reducing the compression ratio of the air conditioning system; or when the step S2 judges that the air conditioning system pressure is too high, the air conditioning system pressure is reduced by a combination of reducing the air conditioning system load and reducing the air conditioning system compression ratio.

Specifically, the method for adjusting the pressure of the air conditioning system comprises at least one of the following three ways:

s3a, reducing the air inlet amount of the evaporator side and/or reducing the compression ratio of the air conditioning system;

s3b, increasing the air inlet amount of the condenser side and/or reducing the compression ratio of the air conditioning system;

s3c, reducing the running frequency of the compressor and/or reducing the compression ratio of the air conditioning system.

And adjusting the pressure of the air conditioning system until the pressure of the exhaust pipe of the compressor meets a second preset condition, and closing the bypass branch or keeping the bypass branch in a closed state. When the pressure Ph of the exhaust pipe of the compressor meets a second preset condition, the pressure of the air conditioning system is reduced to a normal range capable of stably operating.

As shown in fig. 5 and 6, the step of adjusting the pressure of the air conditioning system by reducing the intake air amount at the evaporator side and/or reducing the compression ratio of the air conditioning system in step S3a includes:

when the fan at the evaporator side is a non-lowest wind shield, the wind shield of the fan at the evaporator side is reduced, the air intake at the evaporator side is reduced, and the compressor keeps normal power-on operation so as to reduce the heat exchange quantity at the evaporator side, reduce the load of an air conditioning system and play a role in reducing the pressure of the air conditioning system; and after the third time length delta T3 of the fan windshield at the evaporator side is reduced, continuously detecting the pressure Ph of the exhaust pipe of the compressor, when the pressure Ph of the exhaust pipe of the compressor does not meet a first preset condition, keeping the fan at the evaporator side in the operation of the windshield, when the pressure Ph of the exhaust pipe of the compressor meets a second preset condition, keeping the bypass branch in a closed state, and simultaneously returning to the step S1, operating in a set mode and starting the detection and judgment of the next round. When the compressor exhaust pipe pressure Ph does not meet the first preset condition, the load of the air conditioner is reduced due to the fact that the air inlet amount on the evaporator side is reduced, and therefore the pressure of the air conditioning system is reduced. When the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, the air inlet quantity on the evaporator side is reduced to be insufficient for sufficiently reducing the pressure of the air conditioning system, and the compression ratio of the air conditioning system needs to be reduced or the air inlet quantity of a fan on the evaporator side needs to be further reduced.

When the fan on the evaporator side is the lowest windshield, after the air conditioning system operates for a third time period delta T3 with the lowest windshield, and when the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, the bypass branch is opened, and the compression ratio of the air conditioning system is reduced, so that the pressure of the air conditioning system is reduced. Opening a bypass branch, and after the air-conditioning system operates in the current state for a third time period delta T3, when the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, an alarm device of the air-conditioning system gives out a high-pressure protection operation early warning; and opening the bypass branch, and closing the bypass branch when the pressure Ph of the compressor exhaust pipe does not meet a first preset condition and the pressure Ph of the compressor exhaust pipe meets a second preset condition after the air-conditioning system operates in the current state for a third time period delta T3.

When the fan of the evaporator side of the air conditioning system operates at the lowest windshield for a third time period delta T3 and the pressure Ph of the compressor exhaust pipe does not meet a first preset condition, the pressure of the air conditioning system can be reduced when the fan of the evaporator side operates at the current lowest windshield, whether the pressure Ph of the compressor exhaust pipe is reduced to a range for ensuring normal and stable operation of the air conditioning system needs to be detected, and when the pressure Ph of the compressor exhaust pipe meets a second preset condition, the pressure of the air conditioning system is reduced to the range for normal and stable operation, and the bypass branch needs to be closed.

When the blower at the evaporator side of the air conditioning system operates at the lowest windshield for a third time period delta T3 and the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, the pressure of the air conditioning system is higher when the blower at the evaporator side operates at the current lowest windshield, the normal and stable operation of the air conditioning system is influenced, the compressor is easy to break down, and a bypass branch is required to be opened to reduce the pressure of the air conditioning system by reducing the compression ratio of the air conditioning system; when the bypass branch is opened, after the air conditioning system operates in the current state for a third time period delta T3, and when the pressure Ph of the exhaust pipe of the compressor still meets a first preset condition, it is shown that the pressure of the air conditioning system cannot be fully reduced by reducing the air intake at the evaporator side and reducing the compression ratio of the air conditioner, an alarm prompt needs to be made, and the air conditioning system is manually maintained; when the bypass branch is opened, after the air-conditioning system operates in the current state for a third time period delta T3, when the pressure Ph of the compressor exhaust pipe does not meet a first preset condition, the pressure of the air-conditioning system can be reduced by reducing the pressure-regulating compression ratio, whether the pressure Ph of the compressor exhaust pipe is reduced to a range for ensuring normal and stable operation of the air-conditioning system needs to be detected, and when the pressure Ph of the compressor exhaust pipe meets a second preset condition, the pressure of the air-conditioning system is reduced to the range for normal and stable operation, and the bypass branch needs to be closed.

After the third time length delta T3 of the evaporator side fan windshield is reduced, the evaporator side fan of the air-conditioning system runs for the third time length delta T3 with the lowest windshield, the third time length delta T3 of the bypass branch is opened, the pressure Ph of the compressor exhaust pipe is continuously detected, the time for reducing the air intake of the evaporator side fan or the time for opening the bypass branch is sufficiently long, the pressure Ph of the compressor exhaust pipe is sufficiently reduced, and the detection result can truly and accurately reflect the current pressure of the air-conditioning system. Preferably, the third duration Δ T3 is: not less than 1min, more preferably, Δ T3 is 3 min.

The second preset condition is as follows: the compressor discharge line pressure Ph is less than the first set point P1 for a third duration Δ T3. When the pressure Ph of the compressor exhaust pipe meets a second preset condition, the pressure of the air conditioning system is fully reduced to a normal range capable of stably operating, the air inlet volume at the evaporator side or the compression ratio of the air conditioning system does not need to be further reduced, the bypass branch is kept in a closed state, and meanwhile, the step S1 is returned, the operation is carried out in a set mode, and the next round of detection and judgment is started; and when the pressure Ph of the compressor exhaust pipe does not meet the second preset condition, the pressure of the air conditioning system is not reduced to a normal range capable of stably operating, and the step S2 needs to be returned for judgment again.

As shown in fig. 5 and 7, the method for adjusting the pressure of the air conditioning system by increasing the intake air amount of the condenser side and/or decreasing the compression ratio of the air conditioning system in step S3b includes:

when the fan at the condenser side is not the highest windshield, the fan windshield at the condenser side is improved, the air inlet amount of the fan at the condenser side is increased, and the compressor keeps normal power-on operation so as to improve the heat exchange amount of the condenser and reduce the load of an air conditioning system; and after the third time period delta T3 of the wind shield of the condenser side fan is increased, continuously detecting the pressure Ph of the exhaust pipe of the compressor. When the pressure Ph of the compressor exhaust pipe does not meet a first preset condition, the fan on the condenser side keeps the windshield running, the pressure Ph of the compressor exhaust pipe is continuously detected, when the pressure Ph of the compressor exhaust pipe meets a second preset condition, the bypass branch is kept in a closed state, and meanwhile, the step S1 is returned, the operation is carried out in a set mode, and the next round of detection judgment is started. When the pressure Ph of the exhaust pipe of the compressor does not meet the first preset condition, the load of the air conditioner is reduced due to the fact that the air inlet volume of a fan on the condenser side is increased, and therefore the pressure of an air conditioning system is reduced; when the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, the pressure of the air conditioning system is not sufficiently reduced by increasing the fan on the condenser side, and the compression ratio of the air conditioning system needs to be reduced or the air intake of the fan on the condenser side needs to be further increased.

When the fan on the condenser side is the highest windshield, after the air-conditioning system runs for a third time delta T3 with the highest windshield, the pressure Ph of the exhaust pipe of the compressor is continuously detected, and when the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, the bypass branch is opened, so that the compression ratio of the air-conditioning system is reduced, and the pressure of the air-conditioning system is reduced. Opening a bypass branch, and after the air-conditioning system operates in the current state for a third time period delta T3, when the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, an alarm device of the air-conditioning system gives out a high-pressure protection operation early warning; and opening the bypass branch, and closing the bypass branch when the pressure Ph of the compressor exhaust pipe does not meet a first preset condition and the pressure Ph of the compressor exhaust pipe meets a second preset condition after the air-conditioning system operates in the current state for a third time period delta T3. When the fan of the condenser of the air-conditioning system runs for a third time delta T3 in a highest windshield and the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, the pressure of the air-conditioning system is higher when the fan at the condenser runs at the current highest windshield, the normal and stable running of the air-conditioning system is influenced, the compressor is easy to break down, and the pressure of the air-conditioning system is reduced by opening the bypass branch and reducing the compression ratio of the air-conditioning system; when the bypass branch is opened, after the air conditioning system operates in the current state for a third time period delta T3, and when the pressure Ph of the exhaust pipe of the compressor still meets a first preset condition, it is shown that the pressure of the air conditioning system cannot be fully reduced by increasing the air intake at the condenser side and reducing the compression ratio of the air conditioner, an alarm prompt needs to be made, and the air conditioning system is manually maintained; when the bypass branch is opened, after the air-conditioning system operates in the current state for a third time period delta T3, when the pressure Ph of the compressor exhaust pipe does not meet a first preset condition, it is indicated that the pressure of the air-conditioning system can be reduced by reducing the pressure-regulating compression ratio, and whether the pressure Ph of the compressor exhaust pipe is reduced to a range for ensuring normal and stable operation of the air-conditioning system needs to be detected.

When the fan on the condenser side of the air conditioning system operates at the highest windshield for a third time period delta T3 and the pressure Ph of the compressor exhaust pipe does not meet a first preset condition, the pressure of the air conditioning system can be reduced when the fan on the condenser side operates at the current highest windshield, whether the pressure Ph of the compressor exhaust pipe is reduced to a range for ensuring normal and stable operation of the air conditioning system needs to be detected, and when the pressure Ph of the compressor exhaust pipe meets a second preset condition, the pressure of the air conditioning system is reduced to the range for normal and stable operation, and the bypass branch needs to be closed.

When the fan at the condenser side of the air conditioning system operates at the highest windshield for a third time period delta T3 and the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, the pressure of the air conditioning system is higher when the fan at the condenser side operates at the current highest windshield, the normal and stable operation of the air conditioning system is influenced, the compressor is easy to break down, and the bypass branch is required to be opened to reduce the pressure of the air conditioning system by reducing the compression ratio of the air conditioning system; when the bypass branch is opened, after the air conditioning system operates in the current state for a third time period delta T3, and when the pressure Ph of the exhaust pipe of the compressor still meets a first preset condition, the pressure of the air conditioning system cannot be fully reduced by reducing the compression ratio of the air conditioner, an alarm prompt needs to be given, and the air conditioning system is manually maintained; when the bypass branch is opened, after the air-conditioning system operates in the current state for a third time period delta T3, when the pressure Ph of the compressor exhaust pipe does not meet a first preset condition, the pressure of the air-conditioning system can be reduced by reducing the pressure-regulating compression ratio, whether the pressure Ph of the compressor exhaust pipe is reduced to a range for ensuring normal and stable operation of the air-conditioning system needs to be detected, and when the pressure Ph of the compressor exhaust pipe meets a second preset condition, the pressure of the air-conditioning system is reduced to the range for normal and stable operation, and the bypass branch needs to be closed.

After the third time length delta T3 of the wind shield of the condenser side fan is increased, after the third time length delta T3 of the wind shield of the condenser side fan of the air-conditioning system is operated by the highest wind shield, and the third time length delta T3 of the bypass branch is opened, the pressure Ph of the exhaust pipe of the compressor is continuously detected, the time for increasing the air intake of the condenser side fan or the time for opening the bypass branch is sufficiently long, the pressure Ph of the exhaust pipe of the compressor is sufficiently reduced, and the detection result can truly and accurately reflect the current pressure of the air-conditioning system. Preferably, the third duration Δ T3 is: not less than 1min, more preferably, Δ T3 is 3 min.

The second preset condition is as follows: the compressor discharge line pressure Ph is less than the first set point P1 for a third duration Δ T3. When the pressure Ph of the compressor exhaust pipe meets a second preset condition, the pressure of the air-conditioning system is fully reduced to a normal range capable of stably running, the air inlet volume of a fan at the condenser side is not required to be further increased or the compression ratio of the air-conditioning system is not required to be reduced, the bypass branch is kept in a closed state, and meanwhile, the step S1 is returned, the operation is carried out in a set mode, and the next round of detection and judgment is started; and when the pressure Ph of the compressor exhaust pipe does not meet the second preset condition, the pressure of the air conditioning system is not reduced to a normal range capable of stably operating, and the step S2 needs to be returned for judgment again.

As shown in fig. 5 and 8, the method for adjusting the pressure of the air conditioning system by reducing the operating frequency of the compressor and/or reducing the compression ratio of the air conditioning system in step S3c includes:

when the frequency of the compressor is not the lowest frequency, reducing the running frequency of the compressor, and normally electrifying the compressor to run so as to reduce the load of an air conditioning system; and after the third time length delta T3 of the compressor operation frequency is reduced, continuously detecting the compressor exhaust pipe pressure Ph, when the compressor exhaust pipe pressure Ph does not meet the first preset condition, keeping the current frequency operation of the compressor, when the compressor exhaust pipe pressure Ph meets the second preset condition, keeping the bypass branch in a closed state, and simultaneously returning to the step S1 to operate in a set mode and start the next round of detection and judgment. When the compressor discharge pipe pressure Ph does not satisfy the first preset condition, it is illustrated that the air conditioner load is reduced due to the reduction of the compressor operation frequency, thereby reducing the air conditioning system pressure. When the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, the operation frequency of the compressor is not reduced enough to sufficiently reduce the pressure of the air conditioning system, and the compression ratio of the air conditioning system needs to be reduced or the operation frequency of the compressor needs to be further reduced.

When the operation frequency of the compressor is the lowest frequency, after the compressor of the air-conditioning system operates at the lowest frequency for a third time period delta T3, when the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, the bypass branch is opened, and the compression ratio of the air-conditioning system is reduced, so that the pressure of the air-conditioning system is reduced. Opening a bypass branch, and after the air-conditioning system operates in the current state for a third time period delta T3, when the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, an alarm device of the air-conditioning system gives out a high-pressure protection operation early warning; and opening the bypass branch, and closing the bypass branch when the pressure Ph of the compressor exhaust pipe does not meet a first preset condition and the pressure Ph of the compressor exhaust pipe meets a second preset condition after the air-conditioning system operates in the current state for a third time period delta T3.

When the compressor of the air conditioning system operates at the lowest frequency for the third time period delta T3 and the exhaust pipe pressure Ph of the compressor does not meet the first preset condition, the pressure of the air conditioning system can be reduced when the compressor operates at the current lowest frequency, whether the exhaust pipe pressure Ph of the compressor is reduced to a range which ensures normal and stable operation of the air conditioning system needs to be detected, and when the exhaust pipe pressure Ph of the compressor meets the second preset condition, the pressure of the air conditioning system is reduced to the range which ensures normal and stable operation, and the bypass branch needs to be closed.

When the compressor of the air-conditioning system runs at the lowest frequency for a third time period delta T3 and the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, the situation that the compressor runs at the current lowest frequency, the pressure of the air-conditioning system is high, the normal and stable running of the air-conditioning system is affected, the compressor fault is easy to occur, and the bypass branch needs to be opened to reduce the pressure of the air-conditioning system by reducing the compression ratio of the air-conditioning system; when the bypass branch is opened, after the air conditioning system operates in the current state for a third time period delta T3, and when the pressure Ph of the exhaust pipe of the compressor still meets a first preset condition, the pressure of the air conditioning system cannot be sufficiently reduced by reducing the operating frequency of the compressor and the compression ratio of the air conditioner, an alarm prompt needs to be given, and the air conditioning system is manually maintained; when the bypass branch is opened, after the air-conditioning system operates in the current state for a third time period delta T3, when the pressure Ph of the compressor exhaust pipe does not meet a first preset condition, the pressure of the air-conditioning system can be reduced by reducing the pressure-regulating compression ratio, whether the pressure Ph of the compressor exhaust pipe is reduced to a range for ensuring normal and stable operation of the air-conditioning system needs to be detected, and when the pressure Ph of the compressor exhaust pipe meets a second preset condition, the pressure of the air-conditioning system is reduced to the range for normal and stable operation, and the bypass branch needs to be closed.

After the third time duration delta T3 of the operating frequency of the compressor is reduced, the third time duration delta T3 of the compressor of the air-conditioning system is operated at the lowest frequency, the third time duration delta T3 of the bypass branch is opened, the pressure Ph of the exhaust pipe of the compressor is continuously detected, the time for reducing the operating frequency of the compressor is fully ensured or the time for opening the bypass branch is sufficiently long, the pressure Ph of the exhaust pipe of the compressor is fully reduced, and the detection result can truly and accurately reflect the current pressure of the air-conditioning system. Preferably, the third duration Δ T3 is: not less than 1min, more preferably, Δ T3 is 3 min.

The second preset condition is as follows: the compressor discharge line pressure Ph is less than the first set point P1 for a third duration Δ T3. When the pressure Ph of the compressor exhaust pipe meets a second preset condition, the pressure of the air-conditioning system is fully reduced to a normal range capable of stably running, the running frequency of the compressor or the compression ratio of the air-conditioning system is not required to be further reduced, the bypass branch is kept in a closed state, and meanwhile, the step S1 is returned, the compressor exhaust pipe runs in a set mode and the next round of detection and judgment is started; and when the pressure Ph of the compressor exhaust pipe does not meet the second preset condition, the pressure of the air conditioning system is not reduced to a normal range capable of stably operating, and the step S2 needs to be returned for judgment again.

As shown in fig. 1 and 2, in particular, the air conditioning system of the present invention includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 4, a first throttling assembly 6, an indoor heat exchanger 7, and a first fan 41 and a second fan 71 that adjust heat exchange amounts of the outdoor heat exchanger 4 and the indoor heat exchanger 7. The outlet duct 2 is connected to compressor 1's gas outlet, and muffler 11 is connected to the return-air inlet, still is provided with sensor 21 on outlet duct 2, and sensor 21 sets up between compressor 1's gas outlet and cross valve 3, and sensor 21 sets up to the switch sensor, and when the system detected compressor 1 and is in the state, sensor 21 control switch disconnection stopped the compressor operation, avoided compressor 1 to continuously move the trouble under the state. A filter 5 is disposed between the outdoor heat exchanger 4 and the indoor heat exchanger 7, and the filter 5 serves to store and supply a refrigerant in the refrigeration system. The gas-liquid separator 10 is additionally arranged on the gas return pipe 11 of the compressor 1, when the rotating speed of the first fan 41 or the second fan 71 is reduced, the heat exchange of the outdoor heat exchanger 4 or the indoor heat exchanger 7 is weak, liquid refrigerants may be incompletely evaporated, and when the liquid refrigerants pass through the gas-liquid separator 10, the gas-liquid separator 10 can separate the liquid refrigerants, so that the gaseous refrigerants are ensured to be sucked into the compressor 1, and the liquid impact of the compressor 1 is prevented.

A bypass branch 12 is further arranged on the refrigerant circulation flow channel, one end of the bypass branch 12 is communicated with the air return pipe 11, the other end of the bypass branch 12 is connected to the position between the evaporator and the first throttling component 6, a second throttling component 9 and an electromagnetic valve 8 are arranged on the bypass branch 12, and the electromagnetic valve 8 is used for controlling the on-off of the bypass branch 12. When the electromagnetic valve 8 is in an open state, the refrigerant discharged from the compressor 1 is divided into two parts after heat exchange of the condenser and throttling of the first throttling component 6, one part of the refrigerant returns to the air return pipe 11 after heat exchange of the evaporator, the other part of the refrigerant returns to the air return pipe 11 after secondary throttling of the bypass branch pipe 12, namely, the refrigerant flowing from the bypass branch pipe 12 to the air return pipe 11 is throttled twice, so that the low-temperature refrigerant throttled twice is mixed with the refrigerant returning from the evaporator side of the evaporator, the compression ratio of the air conditioning system is reduced, overheating of the compressor of the air conditioning system, namely, the compression ratio is prevented from being too high, and the operation stability of the compressor is improved.

When the air conditioner operates in a refrigeration mode, as shown in fig. 1 and 3, the outdoor heat exchanger 4 is a condenser, the indoor heat exchanger 7 is an evaporator, the air outlet pipe 2 of the compressor 1 is firstly communicated with an oil port a of the four-way valve 3, a refrigerant flows out through an oil port D and then sequentially flows through the outdoor heat exchanger 4 and the first throttling assembly 6 to be divided into two parts, one part of the refrigerant exchanges heat through the indoor heat exchanger 7 and then returns to the air return pipe 11 after passing through an oil port B and an oil port C of the four-way valve 3, the other part of the refrigerant returns to the air return pipe 11 after passing through the bypass branch 12 for the second throttling, and the low-temperature refrigerant after twice throttling is mixed with the refrigerant returning from the side of the indoor heat exchanger 7 and returns to the inside of the compressor.

When the air conditioner operates in a heating mode, as shown in fig. 2 and 4, the outdoor heat exchanger 4 is an evaporator, the indoor heat exchanger 7 is a condenser, the air outlet pipe 2 of the compressor 1 is firstly communicated with the oil port a of the four-way valve 3, the refrigerant flows out through the oil port D and then sequentially flows through the indoor heat exchanger 7 and the first throttling assembly 6 to be divided into two parts, one part of the refrigerant exchanges heat through the outdoor heat exchanger 4 and then returns to the air return pipe 11 after passing through the oil port B and the oil port C of the four-way valve 3, the other part of the refrigerant returns to the air return pipe 11 after passing through the bypass branch 12 for the second throttling, and the low-temperature refrigerant after twice throttling is mixed with the refrigerant returning from the side of the outdoor heat exchanger 4 and returns to the inside of the compressor.

As shown in fig. 6, as part of the embodiment of the present invention, the method for adjusting the pressure of the air conditioning system by reducing the intake air amount at the evaporator side and/or reducing the compression ratio of the air conditioning system specifically includes the following steps:

step S1, receiving an operation instruction and operating in a set mode; that is, the compressor is powered on, the evaporator side fan is operated according to the set windshield, and the air conditioning system is continuously operated for the first time period Δ T1 in the current mode, and then the step S21 is performed.

When the air conditioner receives a refrigerating mode operation instruction, the indoor heat exchanger is used as an evaporator, and the outdoor heat exchanger is used as a condenser; when the air conditioner receives the heating mode operation instruction, the outdoor heat exchanger is used as an evaporator, and the indoor heat exchanger is used as a condenser.

Step S21, acquiring the pressure Ph of the compressor exhaust pipe;

step S22, judging whether the pressure Ph of the compressor exhaust pipe meets a first preset condition, if so, executing step S30, and controlling the air conditioning system to enter a pressure protection program; if not, returning to step S1, the air conditioning system continues to operate in the current mode.

And step S30, judging whether the evaporator side fan is the lowest windshield, if so, executing step S32, and if not, executing step S31.

When the air conditioning system operates in a refrigeration mode, judging whether the indoor fan is the lowest windshield or not; when the air conditioner operates in a heating mode, whether the outdoor fan is the lowest windshield or not is judged.

And step S31, after the air damper of the evaporator side fan is lowered by one gear and continuously runs for a third time length delta T3, the step S311 is executed.

Step S311, judging whether the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, if so, returning to the step S30, and judging whether the compression ratio of the air conditioning system needs to be reduced or the air inlet volume of a fan at the evaporator side needs to be further reduced; if not, go to step S312.

In step S312, the evaporator side fan keeps the windshield running continuously, and the compressor discharge pipe pressure Ph is continuously detected, and step S33 is executed.

And S32, after the evaporator side fan continuously operates for a third time delta T3 with the lowest windshield, judging whether the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, if so, executing a step S321, and if not, executing a step S33.

And S321, opening the bypass branch, reducing the compression ratio of the air conditioning system, and executing the step S322.

Step S322, after the air conditioning system operates in the current state for the third time period delta T3, judging whether the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, if so, executing step S323, and if not, executing step S33.

And step S323, making a high-voltage protection operation early warning, for example, flashing a fault lamp of the indoor unit to prompt that manual maintenance is needed.

And step S33, judging whether the compressor exhaust pipe pressure Ph meets a second preset condition, if so, executing step S34, otherwise, returning to step S21 and judging again.

And step S34, closing the bypass branch, keeping the electromagnetic valve in a closed state, and continuing to operate in the setting mode of step S1.

According to the method for adjusting the pressure of the air conditioning system by reducing the air intake of the evaporator side and/or reducing the compression ratio of the air conditioning system, the exhaust pressure of the compressor is detected, the pressure value of the air conditioning system can be truly and accurately reflected, errors and delay of detection of the pressure value of the air conditioning system are effectively avoided, the pressure value of the system is accurately and timely controlled within a reasonable range, abnormal shutdown of the air conditioner for a period of time due to high-pressure protection is effectively avoided, the use reliability of a user is improved, and the experience of the user is improved. The load of the air conditioning system is reduced by reducing the fan windshield on the evaporator side, so that the pressure of the air conditioning system is reduced, when the fan on the evaporator side still cannot sufficiently reduce the pressure of the air conditioning system due to the operation of the lowest windshield, the pressure of the air conditioning system is reduced by opening the bypass branch and reducing the compression ratio of the air conditioning system, and on the premise of avoiding high-pressure failure of the compressor, the mode of adjusting the air inlet amount is considered firstly, so that the normal heat exchange of the air conditioning system is ensured.

As shown in fig. 7, as part of the embodiment of the present invention, the method for adjusting the pressure of the air conditioning system by increasing the intake air amount of the condenser side and/or decreasing the compression ratio of the air conditioning system specifically includes the following steps:

step S1, receiving an operation instruction and operating in a set mode; namely, the compressor is powered on to operate, the condenser side fan is operated at a corresponding rotation speed, and the air conditioning system is continuously operated in the current mode for the first time period Δ T1, and then step S21 is executed.

When the air conditioner receives a refrigerating mode operation instruction, the indoor heat exchanger is used as an evaporator, and the outdoor heat exchanger is used as a condenser; when the air conditioner receives the heating mode operation instruction, the outdoor heat exchanger is used as an evaporator, the indoor heat exchanger is used as a condenser, and the indoor fan and the outdoor fan are both direct current motors.

Step S21, acquiring the pressure Ph of the compressor exhaust pipe;

And S30, judging whether the side fan of the condenser is the highest windshield, if so, executing S32, and if not, executing S31.

When the air conditioning system operates in a refrigeration mode, judging whether the outdoor fan is the highest windshield; when the air conditioner operates in a heating mode, whether the indoor fan is the highest windshield or not is judged.

And S31, after the windshield of the condenser side fan is raised to the first gear and continuously runs for the third time duration delta T3, executing the step S311.

Step S311, judging whether the pressure Ph of the compressor exhaust pipe meets a first preset condition, if so, returning to the step S30, and judging whether the compression ratio of the air conditioning system needs to be reduced or the air intake of a fan on the condenser side needs to be further increased; if not, go to step S312.

And step S312, the condenser side fan keeps the windshield continuously running, the pressure Ph of the exhaust pipe of the compressor is continuously detected, and step S33 is executed.

Step S32, after the condenser side fan continuously operates for a third time length delta T3 with the highest windshield, whether the pressure Ph of the exhaust pipe of the compressor meets a first preset condition is judged, if yes, step S321 is executed, and if not, step S33 is executed.

The method for adjusting the pressure of the air conditioning system by improving the air intake of the condenser side and/or reducing the compression ratio of the air conditioning system provided by the embodiment comprises the steps of detecting the exhaust pressure of the compressor and judging whether to enter a pressure protection program, truly and accurately reflecting the pressure value of the air conditioning system, effectively avoiding the error and lag of the detection of the pressure value of the air conditioning system, accurately and timely controlling the pressure value of the system within a reasonable range, effectively avoiding the abnormal shutdown of the air conditioner for a period of time due to high-pressure protection, improving the use reliability of a user and improving the experience of the user. The load of the air conditioning system is reduced by increasing the air intake of the condenser, the pressure of the air conditioning system is further reduced, when the fan on the condenser side still cannot sufficiently reduce the pressure of the air conditioning system under the condition of operation with the highest windshield, the pressure of the air conditioning system is reduced by opening the bypass branch and reducing the compression ratio of the air conditioning system, so that the low-temperature refrigerant subjected to twice throttling is mixed with the refrigerant returning from the evaporator side, the compression ratio of the air conditioning system is reduced, the overheating and overhigh pressure ratio of the compressor of the air conditioning system are prevented, the form of adjusting the air intake is considered primarily on the premise of avoiding the high-pressure fault of the compressor, and the normal heat exchange of the.

As shown in fig. 8, as part of the embodiment of the present invention, the method for adjusting the pressure of the air conditioning system by reducing the operating frequency of the compressor and/or reducing the compression ratio of the air conditioning system specifically includes the following steps:

step S1, receiving an operation instruction and operating in a set mode; that is, the compressor is operated at a set frequency after being powered on, and the air conditioning system is continuously operated for the first time period Δ T1 in the current mode, and then step S21 is performed.

Preferably, the compressor is provided as a rotation speed controllable compressor.

Step S21, acquiring the pressure Ph of the compressor exhaust pipe;

Step S30, determining whether the operating frequency of the compressor is the lowest frequency, if yes, performing step S32, and if no, performing step S31.

And step S311 is executed after the compressor operation frequency is reduced by f and the operation is continued for the third time period delta T3 in step S31.

Step S311, judging whether the pressure Ph of the compressor exhaust pipe meets a first preset condition, if so, returning to the step S30, and judging whether the compression ratio of the air conditioning system needs to be reduced or the running frequency of the compressor needs to be further reduced; if not, go to step S312.

And step S312, the compressor keeps continuously operating at the current frequency, the exhaust pipe pressure Ph of the compressor is continuously detected, and step S33 is executed.

Step S32, after the compressor operation frequency is continuously operated at the lowest frequency for the third duration Δ T3, determining whether the compressor discharge pipe pressure Ph meets the first preset condition, if so, executing step S321, and if not, executing step S33.

The method for adjusting the pressure of the air conditioning system by reducing the running frequency of the compressor and/or reducing the compression ratio of the air conditioning system provided by the embodiment comprises the steps of detecting and judging whether to enter a pressure protection program or not through the exhaust pressure of the compressor, truly and accurately reflecting the pressure value of the air conditioning system, effectively avoiding errors and hysteresis of detection of the pressure value of the air conditioning system, accurately and timely controlling the pressure value of the system within a reasonable range, effectively avoiding abnormal shutdown of the air conditioner for a period of time due to high-pressure protection, improving the use reliability of a user and improving the experience of the user. The method is characterized in that the load of the air conditioning system is reduced by reducing the running frequency of the compressor, the pressure of the air conditioning system is further reduced, when the compressor still cannot sufficiently reduce the pressure of the air conditioning system when running at the lowest frequency, the pressure of the air conditioning system is reduced by opening the bypass branch and reducing the compression ratio of the air conditioning system, so that the low-temperature refrigerant subjected to twice throttling is mixed with the refrigerant returning from the evaporator side, the compression ratio of the air conditioning system is reduced, and the overheating and the over-high pressure ratio of the compressor of the air conditioning system are prevented.

As a part of the embodiment of the present invention, there is also provided an air conditioner including the air conditioning system described above, and capable of executing the air conditioning system pressure protection control method described above, where the air conditioner of this embodiment further includes:

the detection unit is used for detecting the exhaust pressure of the compressor and acquiring the running time of the air conditioning system;

and the judging unit is used for judging the size of the compressor relative to the first set value.

The air conditioner of the embodiment further comprises a computer readable storage medium and a processor, wherein the computer readable storage medium stores a computer program, and when the computer program is read and executed by the processor, the air conditioner system pressure protection control method is realized.

As a part of the embodiments of the present invention, there is also provided a computer-readable storage medium storing a computer program, which is read and executed by a processor to implement the pressure protection control method of the air conditioning system as described above.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A pressure protection control method of an air conditioning system comprises a refrigerant circulating flow channel which connects a compressor, an evaporator and a condenser together in series, wherein a first throttling component is arranged on the refrigerant circulating flow channel, the pressure protection control method is characterized by further comprising a bypass branch, the bypass branch is connected with the evaporator and the condenser in parallel, a second throttling component is arranged on the bypass branch, and the control method comprises the following steps:

and adjusting the load of the air conditioning system and/or adjusting the compression ratio of the air conditioning system through the bypass branch to adjust the pressure of the air conditioning system.

2. The pressure protection control method of the air conditioning system as claimed in claim 1, wherein when the compressor exhaust pipe pressure Ph meets a first preset condition, the control unit executes a pressure protection program to adjust the air conditioning system pressure, and when the air conditioning system pressure is adjusted until the compressor exhaust pipe pressure meets a second preset condition, the bypass branch is closed.

3. The air conditioning system pressure protection control method according to claim 1, wherein the method of adjusting the pressure of the air conditioning system comprises:

at least one of the above three ways.

4. The pressure protection control method of the air conditioning system as claimed in claim 3, wherein the process of reducing the intake air amount at the evaporator side and/or reducing the compression ratio of the air conditioning system comprises:

when the fan on the corresponding side of the evaporator is in a non-lowest windshield, reducing the air inlet volume of the fan on the evaporation side, and keeping the compressor in normal power-on operation; when the fan on the corresponding side of the evaporator is the lowest windshield and the pressure Ph of the compressor exhaust pipe meets a first preset condition, the compression ratio of the air conditioning system is reduced by opening the bypass branch.

5. The pressure protection control method of an air conditioning system according to claim 4, characterized in that after the third duration Δ T3 of the damper of the blower on the evaporator side is reduced, the discharge pipe pressure Ph of the compressor is continuously detected, the blower on the evaporator side keeps the damper in operation when the discharge pipe pressure Ph of the compressor does not satisfy the first preset condition, and the bypass branch is kept in a closed state when the discharge pipe pressure Ph of the compressor is continuously detected to satisfy the second preset condition.

6. The pressure protection control method of the air conditioning system according to claim 4, characterized in that after the bypass branch is opened and the air conditioning system is operated for a third time period Δ T3, when the compressor discharge pipe pressure Ph meets a first preset condition, the warning device of the air conditioning system gives a pre-warning for protection operation, and when the compressor discharge pipe pressure Ph does not meet the first preset condition and when the compressor discharge pipe pressure Ph meets a second preset condition, the bypass branch is closed.

7. The pressure protection control method of the air conditioning system according to claim 3, wherein the process of increasing the air intake of the condenser side and/or decreasing the compression ratio of the air conditioning system comprises:

when the fan at the condenser side is in a non-highest windshield, the air inlet volume of the fan at the condenser side is increased, and the compressor keeps normal power-on operation; when the fan on the condenser side is the highest windshield and the pressure Ph of the compressor exhaust pipe meets a first preset condition, the compression ratio of the air conditioning system is reduced by opening the bypass branch.

8. The pressure protection control method of the air conditioning system according to claim 7, wherein after the third duration Δ T3 of the damper of the fan on the condenser side is increased, the pressure Ph of the discharge pipe of the compressor is continuously detected, when the pressure Ph of the discharge pipe of the compressor does not satisfy the first preset condition, the fan on the condenser side keeps the damper in operation, and when the pressure Ph of the discharge pipe of the compressor is continuously detected to satisfy the second preset condition, the bypass branch is kept in a closed state.

9. The pressure protection control method of the air conditioning system according to claim 7, characterized in that after the bypass branch is opened and the air conditioning system is operated for a third time period Δ T3, when the compressor discharge pipe pressure Ph meets a first preset condition, the air conditioning system alarm device gives a pre-warning of the protection operation, and when the compressor discharge pipe pressure Ph does not meet the first preset condition and when the compressor discharge pipe pressure Ph meets a second preset condition, the bypass branch is closed.

10. The air conditioning system pressure protection control method according to claim 3, wherein the process of reducing the operating frequency of the compressor and/or reducing the compression ratio of the air conditioning system comprises:

when the frequency of the compressor is not the lowest frequency, the operation frequency of the compressor is reduced, and when the operation frequency of the compressor is the lowest frequency and the pressure Ph of the exhaust pipe of the compressor meets a first preset condition, the compression ratio of the air-conditioning system is reduced by opening the bypass branch.

11. The pressure protection control method of the air conditioning system according to claim 10, wherein after the third time period Δ T3 for the compressor operation frequency is reduced, the compressor discharge pipe pressure Ph is continuously detected, the compressor keeps operating at the current frequency when the compressor discharge pipe pressure Ph does not satisfy the first preset condition, and the bypass branch is kept in a closed state when the compressor discharge pipe pressure Ph is detected to satisfy the second preset condition.

12. The pressure protection control method of the air conditioning system according to claim 10, wherein the bypass branch is opened, after the air conditioning system operates for a third time period Δ T3, the air conditioning system warning device gives a pre-warning of protection operation when the compressor discharge pipe pressure Ph meets a first preset condition, and the bypass branch is closed when the compressor discharge pipe pressure Ph does not meet the first preset condition and the compressor discharge pipe pressure Ph meets a second preset condition.

13. The pressure protection control method of the air conditioning system according to any one of claims 2 and 4 to 12, wherein the first preset condition is that: and the pressure Ph of the exhaust pipe of the compressor is greater than or equal to a first set value P1 in any continuous second time period delta T2, the second time period delta T2 is set according to the property of the compressor, and the first set value P1 is a pressure critical value influencing the stable operation of the air conditioning system.

14. The pressure protection control method of an air conditioning system according to any one of claims 2, 5 to 6, 8 to 9, and 11 to 12, wherein the second preset condition is that: the compressor discharge pipe pressure Ph is less than a first set point P1 for a third duration Δ T3, where the first set point P1 is a pressure threshold that affects stable operation of the air conditioning system.

15. An air conditioner comprising a processor and a computer readable storage medium storing a computer program, the computer program being read by the processor and when executed, implementing the air conditioning system pressure protection control method of any one of claims 1-14, the air conditioner further comprising: the detection unit is used for detecting the exhaust pressure of the compressor and acquiring the running time of the air conditioning system;